He had planned to attend summits in Indonesia and Brunei as part of what had originally been a four-nation, week-long Asia trip. Obama had already abandoned visits to Malaysia and the Philippines earlier this week because of his budget struggle with Republicans in Congress.

Mr Obama's decision means that US secretary of state John Kerry, who unsuccessfully bid for the White House in 2004, will get the chance to be presidential.

Mr Kerry will now lead heavyweight US delegations to the Asia Pacific Economic Cooperation Forum in Bali and the East Asia Summit in Brunei.

Mr Kerry had been in Tokyo for security talks and was already planning to attend both meetings but only in a supporting role for Mr Obama.

He found out earlier in the week that he would be visiting Malaysia and the Philippines in Mr Obama's place next week.

Last night, the President has issued an angry challenge to Republican leaders to "stop this farce" and end the shutdown immediately by standing up to "extremists" within their own party.

Three days after swathes of the government closed and 800,000 public workers were put on unpaid leave, Mr Obama called on Republicans to hold a vote on a simple funding Bill "with no partisan strings attached".

Citing growing numbers of Republican congressmen who said they were prepared to reopen the government without any concessions on the president's health care reforms, Mr Obama urged House leaders to "call a vote".

"Send the Bill to the floor, let everybody vote, it will pass, send me the Bill, I will sign it, the shutdown will be over and we can get back to the business of governing and helping the American people," Mr Obama said.

"Take a vote, stop this farce, and end this shutdown right now."

Despite White House pressure, Republicans have shown no sign of backing away from demands that Mr Obama roll back his health care law in exchange for reopening the government. Mr Obama dismissed their demands as an "obsession".

John Boehner, the Republican speaker of the House, met Mr Obama for more than an hour on Wednesday for what he called a "polite" but unproductive discussion. In private, Republicans said they believed the White House's refusal to negotiate until the government was reopened would eventually backfire on Mr Obama.

Senator Rand Paul, a leading Tea Party Republican, was caught on a TV microphone saying he thought Democrats had not "poll-tested" their position on not negotiating. "I think it's awful for (Democrats) to say that over and over again," Mr Paul said. "I know we don't want to be here, but we're gonna win this, I think."

About 20 Republicans, many of whom represent districts with large numbers of federal employees, have said publicly they would vote for a "clean" funding Bill that has no impact on the health care law.

If Republican rebels were joined by all 200 Democrats, there would be enough votes in the House to pass a Bill which could be accepted by the Senate and White House, ending the crisis.

Peter King, one of the leading Republican rebels, said conservatives' determination to hold out for concessions on Obamacare was "absolute insanity", adding: "We have allowed them to hijack our party."

But he acknowledged that he and other moderates were unlikely to be able to force a quick end to the standoff.

The president took his argument outside of Washington yesterday, delivering a campaign-style speech at a construction company in Maryland which had benefited from loans granted by a now-closed government agency.

RECKLESS

"There is one way out of this reckless and damaging Republican shutdown: Congress has to pass a budget that funds our government with no partisan strings attached," he said.

Mr Obama mockingly cited a quote from Marlin Stutzman, a junior Republican congressman, who said: "We're not going to be disrespected; we've got to get something out of this, and I don't know what that even is."

The president added: "You've already got the opportunity to help businesses like this one, workers like these. So the American people aren't in the mood to give you a goodie bag to go with it."

The US Treasury meanwhile warned that if Congress failed to lift the debt ceiling, the legal amount of money America can borrow to service its debt, by October 17 it could trigger a fresh global financial crisis.